Internet protocol (IP) multimedia subsystem (IMS) is a standardized next generation networking (NGN) architecture for providing mobile and fixed multimedia services. IMS uses a session initiation protocol (SIP) and runs over IP. IMS can be used for many different services, (e.g., instant messaging, video streaming, voice over IP (VoIP), and any other IP-based services).
The goal of IMS is to provide all the services, current and future, that the Internet provides. One of the methods used to provide these services is through an IMS application server. The IMS application server is a network entity that hosts and executes one or more IP services. An application server is triggered to provide a service by a serving call session control function (S-CSCF) which is a central node in the IMS signaling plane.
The IEEE 802.21 standard defines mechanisms and procedures that aid in the execution and management of inter-system handovers. Under IEEE 802.21, three main services can be accessed by mobility management applications in order to aid in the management of handover operations and system discovery and selection. These services include an event service, an information service, and a command service. These services do not depend on each other and, as a result, may be delivered independently.
Currently, there are no interfaces or mechanisms that describe how IEEE 802.21 services may interact with existing mobility management and handover functionality already defined within the relevant third generation partnership project (3GPP) or similar wireless standards specifications. There are no procedures or functionality to integrate IEEE 802.21 services within 3GPP or other wireless standards unless existing mobility management mechanisms and handover procedures are modified. Therefore, an MIH application server that is capable of integrating MIH services in a 3GPP or other wireless standards based network is required.